Answer:r=1.104
Step-by-step explanation:
Given
First term a_1=256
[tex]a_8=512[/tex]
Also [tex]a_8[/tex] can also be written in
[tex]a_8=ar^7[/tex]
where r=common difference
[tex]512=256r^7[/tex]
[tex]2=r^7[/tex]
[tex]r=\left ( 2\right )^{\frac{1}{7}}[/tex]
r=1.104
